Brush for dynamo-electric machines



(No Model.)

J. B. WALLACE. BRUSH FOR DYNAMO ELECTRIC MAUHINES. No. 531,707;

Patented Jan. 1, 1895.

WITNEIEEEI |NVENTUfi 2346M ATTUFWEY arren STATES PATENT Cr mea.

JOHN B. \VALIAACE, OF ANSONIA, CONNECTICUT, ASSIGNOR TO THE IVALLACEELECTRIC COMPANY, OF ILLINOIS.

BRUSH FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 531,707, dated January1, 1895.

Application filed April 30, 1894.

To aZZ whom it may concern.-

Be it known that I, JOHN B. \VALLAOE, a citizen of the United States,residing at Ansonia, in the county of New Haven and State ofConnecticut, have invented certain new and useful Improvements inBrushes for Dynamo-Electric Machines, of which the following is aspecification.

My invention relates to brushes for dynamo-electric machines and has forits object to provide a brush in which there shall be a minimum oftendency to cause sparking.

My invention is illustrated in the accompanying drawings, Wherein-Figure 1 is a perspective view of a brush. Fig. 2is a cross sectionthrough the same. Fig. 3 is a cross section through a modification. Fig.4 is a cross section through a different form of brush. Fig. 5 is aperspective of the preferred form of brush, somewhat diagrammatic.

Like parts are indicated by the same letters in all the figures.

A is the body of the brush, composed preferably of metallic gauze orcloth folded in the form indicated. This cloth or gauze is prefreablycomposed of a good conductor so that the body of the brush is composedof high conducting material.

B B are strips on the sides of the body and they are of high resistancemetal or material and they are secured to the body in any desired manneras by clamps or by soldering the parts at the end of the brush.

C is a wrapping of high resistance material which passes entirely aroundthe body of the brush covering both sides and edges, and is composed ofany desired substance if only it be of high resistance, and it is formedand attached in any desired manner.

D is a wrapper of high resistance metallic gauze or cloth and it isformed continuous with or attached to the metallic gauze or cloth of thebody of the brush and is then Wrapped about the body of the brush asmany times as may be necessary. In this latter,

which is the preferred form of my brush, I have one mass of gauze ormetallic cloth, the

Serial No. 509,511. (No model.)

body portion of high conducting power, and the outer folds or coveringwhich entirely surround the body, composed of high resist ance gauze orcloth.

It is quite evident that the high resistance wrapping of any kind of.material, preferably of gauze or cloth, may be applied to a body ofother than gauze or cloth construction, and it is equally evident thatthe high resistance gauze or cloth may be applied to the sides only ofthe body of the brush. By having the entire brush made of gauze or wirecloth the sparking is reduced to a minimum, the body of the brush beingprotected at its edges as Well as at its sides, and the gauze or clothof the high resistance material being closely set to the body of thebrush. This same result to a degree, comes about when the highresistance gauze wrapping is used to surround a brush Whose body iscomposed of material other than wire cloth or gauze. On the other hand,the wire cloth or gauze of the outer or high resistance portion of thebrush very closely incorporates itself with the cloth or gauze of thebody, so that the separation of the parts is impossible to the degreewhich is possible in the case of laminated brushes. This is due to thefact that the masses or projecting ends of the fibers of the gauze ofthe brush become entangled and entwined and associated together, andthus in the process of use the separation of the high from the lowresistance material is reduced to a minimum.

In some cases the brush may be surrounded by a high resistance materialnot in the form of gauze or cloth, though I prefer the latter.

I claim- 1. A brush for dynamo-electric machines consisting of a body ofgauze or cloth composed of a good conducting material with an enclosingor surrounding Wrapper of gauze or cloth of a high resistance substanceor material.

2. A brush for dynamo-electric machines consisting of a body composed ofgauze or cloth of a good conducting substance or ma terial, with layersof cloth or gauze of high resistance material on the sides thereof.

8. A brush for dynamo-electric machines covers the sides and edges ofsaid body and consisting of a body of good conducting mais itselfcomposed of high resistance mateterial with a surrounding coveringcomposed rial the Whole constituting a flexible brush. IO

of a gauze or cloth of high resistance material. JOHN B. W ALLAOE. 5 4.A brush for dynamo-electric machines Witnesses:

consisting of a body of good conducting ma- J NO. H. OOULTER,

terial with a surrounding covering; which W'ALTER J. GUNTHORP.

